Amorphous silicon solar cells : comparison of p-i-n and n-i-p structures with zinc-oxide frontcontact

Wieder, S.

Dissertation / PhD Thesis/Book

Amorphous silicon solar cells : comparison of p-i-n and n-i-p structures with zinc-oxide frontcontact

Wieder, S. (Corresponding author)FZJ*

1999
Forschungszentrum, Zentralbibliothek Jülich

Jülich : Forschungszentrum, Zentralbibliothek, Berichte des Forschungszentrums Jülich 3721, (1999) = Aachen, Techn. Hochsch., Diss., 1999

Please use a persistent id in citations: http://hdl.handle.net/2128/20560

Report No.: Juel-3721

Abstract: This work compares amorphous silicon solar cells in the p-i-n and n-i-p structure. In both cell structures, sputtered Zinc-Oxide (ZnO) films were established as front contact . We developed smooth TCO films with high conductivity and high transparency . The required surface texture is achieved by a post deposition wet chemical etching step in diluted HC1 . In both cell structures, a contact barrier emerges at the amorphous-p/ZnO interface . In both cases, the negative effects of the barrier on the electrical properties of the solar cell are avoided by the application of highly conductive, microcrystalline p-layers (μc-p), which were developed with the RF as well as the VHF deposition technique . We were able to clearly show that the optimum p-layer structure for a-Si:H solar cells with ZnO frontcontact is an amorphous/microcrystalline double-layer : The thin ,uc-p-layer provides a low-ohmic ZnO/p-contact, while an amorphous phase is essential in order to build up a high open-circuit voltage (Voc) . The optical optimization led to high quantum efficiencies in both cell types and showed an advantage of the n-i-p structure in the laboratory caused by the possible antireflection design of the frontcontact in this structure. We confirmed literature reports asserting a drop in the i pe of p-i-n cells when using elevated substrate temperatures during deposition of the i-layer material, while the decrease in for the n-i-p cells simply correlates with the decrease of the band gap of the absorber material . The implementation of the developed materials led to a highly efficient a, Si :H/a-Si:H tandem cell in the p-i-n structure on sputtered ZnO with 9 .2 % stable efficiency after 900 h of light soaking . The transfer of the achieved results to module production is performed in an joint venture between research and industry.

Note: Record converted from VDB: 12.11.2012
Note: Aachen, Techn. Hochsch., Diss., 1999

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